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National Boards => General Highway Talk => Topic started by: Scott5114 on December 21, 2009, 10:30:38 AM

Title: Cantilevers from hell
Post by: Scott5114 on December 21, 2009, 10:30:38 AM
Quote from: architect77 on December 21, 2009, 07:40:50 AM
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi174.photobucket.com%2Falbums%2Fw102%2Farchitect77%2Fi85ncexit132_02.jpg&hash=060b5001d9f1acb28879c3197e6591cce07dfd67)
I wish someone would create a "Cantilevers from Hell" thread for those extremely far-reaching overheads that appear to be pushing the limit.

Make it so.
Title: Re: Cantilevers from hell
Post by: myosh_tino on December 21, 2009, 01:57:15 PM
Not quite sure what Architech77 means by "extremely far-reaching overheads that appear to be pushing the limit" but sign bridges of that style are very common in California...

(https://www.aaroads.com/california/images580/i-580_wb_exit_047_05.jpg)
Title: Re: Cantilevers from hell
Post by: wytout on December 21, 2009, 02:02:26 PM
well here's one where the arm's obscenity is a relative thing I guess.  I mean it's long, but maybe not the longest.  TOO long for the puny little sign attached to the CENTER of it though.  That's for sure....

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.wytout.com%2Fpersonal%2Fugly10.JPG&hash=08c7cf27a49cba0412b22502ee167c68aeb8cdf0)
Title: Re: Cantilevers from hell
Post by: Brandon on December 21, 2009, 03:17:39 PM
A goody from IDOT, complete with over-extended arm, on I-355 south just before Army Trail Road:

http://maps.google.com/maps?hl=en&ie=UTF8&ll=41.943977,-88.037953&spn=0,359.995505&t=h&z=19&layer=c&cbll=41.944095,-88.037705&panoid=exbyGQR0CNZ-169c3UY5Dw&cbp=12,189.09,,0,-3.32

The far left of the sign used to hold a "FREEWAY ENDS" sign until December 1989.

And yes, IIRC, it is button copy.
Title: Re: Cantilevers from hell
Post by: un1 on December 21, 2009, 03:35:49 PM
The MTO never puts them far out, only close in. Unless they are on a grade, I think the Gardiner has some that are far out.
Title: Re: Cantilevers from hell
Post by: Ian on December 21, 2009, 03:36:28 PM
I think he is trying to say cantilevers that are way to far out onto the highway and may be one to many signs on one cantilever. I may have some examples of what this thread is about:

http://picasaweb.google.com/Iansignal/MaineTrafficSignalsAndRoadSigns#5377324137609225138

http://picasaweb.google.com/Iansignal/NewHampshireTrafficSignalsAndRoadSigns#5350720044231910450

http://picasaweb.google.com/Iansignal/NewHampshireTrafficSignalsAndRoadSigns#5350720142469662002

http://picasaweb.google.com/Iansignal/NewHampshireTrafficSignalsAndRoadSigns#5350720454354345538

http://picasaweb.google.com/Iansignal/NewHampshireTrafficSignalsAndRoadSigns#5350721135361744066

http://picasaweb.google.com/Iansignal/NewHampshireTrafficSignalsAndRoadSigns#5350721180960720082

http://picasaweb.google.com/Iansignal/NewHampshireTrafficSignalsAndRoadSigns#5353723142253789538

http://picasaweb.google.com/Iansignal/NewHampshireTrafficSignalsAndRoadSigns#5353723149624562194

http://picasaweb.google.com/Iansignal/NewHampshireTrafficSignalsAndRoadSigns#5353972463163727298

(spend some time in NH and RI, and you will see many examples)

http://picasaweb.google.com/Iansignal/RhodeIslandTrafficSignalsAndRoadSigns#5324328700204456978

http://picasaweb.google.com/Iansignal/RhodeIslandTrafficSignalsAndRoadSigns#5324328837884653314

http://picasaweb.google.com/Iansignal/RhodeIslandTrafficSignalsAndRoadSigns#5324329030882497554

http://picasaweb.google.com/Iansignal/RhodeIslandTrafficSignalsAndRoadSigns#5324329158889923026

http://picasaweb.google.com/Iansignal/RhodeIslandTrafficSignalsAndRoadSigns#5324329768884763330

http://picasaweb.google.com/Iansignal/RhodeIslandTrafficSignalsAndRoadSigns#5324330662025025122

Continuing with other states...

http://picasaweb.google.com/Iansignal/OldDelDOTFreewaySigns#5313210588431081490

NJ has a bunch:

http://picasaweb.google.com/Iansignal/NewJerseyTrafficSignalsAndRoadSigns#5341344115943163410

http://picasaweb.google.com/Iansignal/NewJerseyTrafficSignalsAndRoadSigns#5341344126349446482

http://picasaweb.google.com/Iansignal/NewJerseyTrafficSignalsAndRoadSigns#5341344175253326658

http://picasaweb.google.com/Iansignal/NewJerseyTrafficSignalsAndRoadSigns#5341344232790614178

http://picasaweb.google.com/Iansignal/NewJerseyTrafficSignalsAndRoadSigns#5341344384529912066

http://picasaweb.google.com/Iansignal/NewJerseyTrafficSignalsAndRoadSigns#5341342999218586354
Title: Re: Cantilevers from hell
Post by: yanksfan6129 on December 21, 2009, 06:39:55 PM
Quote from: PennDOTFan on December 21, 2009, 03:36:28 PM
I think he is trying to say cantilevers that are way to far out onto the highway and may be one to many signs on one cantilever. I may have some examples of what this thread is about:

http://picasaweb.google.com/Iansignal/NewHampshireTrafficSignalsAndRoadSigns#5353723149624562194

The shield for US 4 is also 3di width on that sign, yet the I-393 shield looks squished. Odd.
Title: Re: Cantilevers from hell
Post by: Ian on December 21, 2009, 07:24:56 PM
Quote from: yanksfan6129 on December 21, 2009, 06:39:55 PM
Quote from: PennDOTFan on December 21, 2009, 03:36:28 PM
I think he is trying to say cantilevers that are way to far out onto the highway and may be one to many signs on one cantilever. I may have some examples of what this thread is about:

http://picasaweb.google.com/Iansignal/NewHampshireTrafficSignalsAndRoadSigns#5353723149624562194

The shield for US 4 is also 3di width on that sign, yet the I-393 shield looks squished. Odd.

Yeah, I noticed the same thing.
Title: Re: Cantilevers from hell
Post by: architect77 on December 21, 2009, 10:35:09 PM
These cantilevered assemblies must resist the force being applied from the sign's weight. This force essentially doubles with every foot of distance between the sign and support post. A 200 lb. overhead jutting out 20' is the same as supporting a 4,000 lb. sign 1' from the post. So whether it's the distance, use of skinny trusses, or huge signs being supported which you know weigh a sh*tload, anyone know of any "cantilevers from hell"?
NCDOT might be getting a tad over-confident....
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi174.photobucket.com%2Falbums%2Fw102%2Farchitect77%2Fwendovercantilever.jpg&hash=79503f22d98746d6ad262c12f31c3b7ada3cea6f)
Overhead on Raleigh's Beltline. I grew up in Louisburg.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi174.photobucket.com%2Falbums%2Fw102%2Farchitect77%2Flouisburgcantilever.jpg&hash=b639cdfdbc6806ff3c99e7c5b24a9fac6286de6d)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi174.photobucket.com%2Falbums%2Fw102%2Farchitect77%2Fleecantilever.jpg&hash=eebc9bda8ed520518962a91b552222063406f413)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi174.photobucket.com%2Falbums%2Fw102%2Farchitect77%2Fglenwoodcantilever.jpg&hash=ea834e766cfc3975d8b3a573244743138a310624)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi174.photobucket.com%2Falbums%2Fw102%2Farchitect77%2Fmounthopecantilever.jpg&hash=bdf6cbaa8e8c2e23f5ae13eab3a1b3a0be097908)
Title: Re: Cantilevers from hell
Post by: Ian on December 22, 2009, 08:16:02 PM
Not a cantilever, but a very wiiiide sign gantry that could be shown here (there are many like these accross New Hampshire):

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Flh6.ggpht.com%2F_ZkmN2RrOJxw%2FSkGTtYwLVHI%2FAAAAAAAAI7I%2FLt2WjI4csQ8%2Fs720%2FIMG_6029.JPG&hash=77875a67a65a9fcf0586228ca2a43702bfd2923d)

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Flh5.ggpht.com%2F_ZkmN2RrOJxw%2FSk0h1Mp3gUI%2FAAAAAAAAKH0%2Fn9xUeNCdAcY%2Fs720%2FIMG_6978.JPG&hash=1ec7cb6e01a8062f9b10c41e9e93dedf1e426218)

helping Ian solve a problem with directly linking to Picasa images ... is it working yet?

Yup, I think I may have got it!
Title: Re: Cantilevers from hell
Post by: mightyace on December 22, 2009, 09:03:04 PM
One of Tennessee's many Cantilevers from hell:

This one on I-65 NB near Exit 74

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm3.static.flickr.com%2F2753%2F4207808146_c747ab7571_o.jpg&hash=1203f4076341b195c0be8debb7ce2986855d8fa1)
2009-12-22 I-65 Exit 74 TN 254 by mightyace, on Flickr (http://www.flickr.com/photos/mightyace/4207808146/)

Sorry about the low image quality, I just had my Droid phone with me today.  Now while it's 5mp, I'm still learning and I don't know why it's just 640x480.
Title: Re: Cantilevers from hell
Post by: hbelkins on December 22, 2009, 09:16:07 PM
Tennessee actually had a sign assembly like this fall on I-65 last year, correct?
Title: Re: Cantilevers from hell
Post by: mightyace on December 22, 2009, 09:17:53 PM
Quote from: hbelkins on December 22, 2009, 09:16:07 PM
Tennessee actually had a sign assembly like this fall on I-65 last year, correct?

Yes, they did on SB I-65 near Exit 68.  This is a section of highway I travel on almost daily.  I commented on this in another thread.

https://www.aaroads.com/forum/index.php?topic=1324.msg30976#msg30976

EDIT: Added link.
Title: Re: Cantilevers from hell
Post by: mightyace on February 02, 2010, 07:31:06 PM
During my "website weekend," I got a few more examples uploaded to Flickr:

I-65 NB @ TN 96
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm5.static.flickr.com%2F4030%2F4316944033_04bac3bdf1.jpg&hash=45651abda1c55bef973cd71c6634ced31e0b0876)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm5.static.flickr.com%2F4024%2F4282650155_94a234f285.jpg&hash=960fb85aeaea5bc7b2af22051e444169357cc058)

I-65 NB @ TN SSR 255 - Harding Place
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm3.static.flickr.com%2F2714%2F4317692060_023fe59bc1.jpg&hash=d7b8dc28458ee579d5f0d199206507e361fdf9c8)

Secondary signage for TN 840 exits off of I-65 NB
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm3.static.flickr.com%2F2684%2F4282648191_e5cd092c5f.jpg&hash=c9547fb254d21d5a8eb719b974518029d45c1bca)

US 31 SB @ Saturn Parkway
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm3.static.flickr.com%2F2682%2F4321816244_b3f2866cc7.jpg&hash=f29d7b971204789373c60a3f351afe4503dcbcb4)

Of the ones I've gotten so far, I think this one takes the cake:

TN SSR 255 WB @ I-65
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm3.static.flickr.com%2F2802%2F4317695446_80533fa653.jpg&hash=e4cf61e9092d6a5ab2ba19c3fadbf5117f18fca9)
Title: Re: Cantilevers from hell
Post by: joseph1723 on February 02, 2010, 08:05:56 PM
Here's the widest one I've seen in Ontario so far:
ON 427 NB at ON 27 collector transfer
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fimg269.imageshack.us%2Fimg269%2F7295%2Fdscn6471.jpg&hash=64e6136bcc65ebdf28d5419f17c8612590c9dd69)

This one just has a wide BGS on it:
ON QEW Hamilton Bound at Cawthra
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fimg525.imageshack.us%2Fimg525%2F5131%2Fdscn6069.jpg&hash=5de21736fdf15498c7825925b4ee2a77d14c9bb9)

I think MTO only started using a lot of cantilevers structures in the past five or so years. I recall almost all of the signs before then were one sign bridges.  Both of the cantilevers pictured replaced a older sign bridge though. I've seen more and more supports for cantilevers getting installed now.   
Title: Re: Cantilevers from hell
Post by: aswnl on February 05, 2010, 08:17:48 AM
Some examples from Europe:

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.autobahnatlas-online.de%2FBildergalerie%2FA3o_0015.jpg&hash=f1e9be48f224e4410878836cedf320c01e04ba76)

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.autobahnatlas-online.de%2FBildergalerie%2FA4_Koeln_Aach_01.jpg&hash=0ee5f66b70de7620ae87894ecd995df036a7eadb)

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.autobahnatlas-online.de%2FBildergalerie%2FA4_Koeln_Aach_50.jpg&hash=80525a8b9af7bdadf187a273e2794de255db0215)

Title: Re: Cantilevers from hell
Post by: shoptb1 on February 05, 2010, 08:45:39 AM
Quote from: aswnl on February 05, 2010, 08:17:48 AM
Some examples from Europe:

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.autobahnatlas-online.de%2FBildergalerie%2FA3o_0015.jpg&hash=f1e9be48f224e4410878836cedf320c01e04ba76)

This example, in particular, looks as though it would be less-than-optimal for supporting the sign-load, unless this sign is made from lighter materials than its North American counterparts.  I remember seeing a study a few years back regarding the various cantilever designs used in the United States (comparing single-support (monotube), and various double-support truss designs) and one of the largest factors was related to additional snow/ice load in the winters.  Single-support cantilevers were shown to be the worst for colder climates.  This sign looks to be near Giessen (north of Frankfurt a.M.), so I'm guessing that they would also deal with winter precipitation.  Anyone else have any thoughts here?

Title: Re: Cantilevers from hell
Post by: aswnl on February 05, 2010, 04:09:31 PM
The largest factor on overhead signs isn't (added ice) weight, but windforce.
Title: Re: Cantilevers from hell
Post by: Chris on February 05, 2010, 04:19:57 PM
Italy sometimes installs these monsters:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi50.tinypic.com%2F2irralf.jpg&hash=9199505358b4725ab03b250acd9209fdd5d6bd1a)

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.matildi.com%2Fimages%2Flotto5_gra_finale.jpg&hash=0c90ac2c69bb7ee9385daa1765a32a71b959a51d)


(don't get me started on the horrible Italian signage)
Title: Re: Cantilevers from hell
Post by: shoptb1 on February 05, 2010, 05:20:34 PM
Quote from: aswnl on February 05, 2010, 04:09:31 PM
The largest factor on overhead signs isn't (added ice) weight, but windforce.

Yeah, for some reason, I think this study was specifically related to winter-related conditions, but they also factored wind-force into all of the calculations. At any rate, that single-beam design would still have a lot of stress on a single point.
Title: Re: Cantilevers from hell
Post by: shoptb1 on February 05, 2010, 05:23:39 PM
Quote from: Chris on February 05, 2010, 04:19:57 PM
Italy sometimes installs these monsters

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.matildi.com%2Fimages%2Flotto5_gra_finale.jpg&hash=0c90ac2c69bb7ee9385daa1765a32a71b959a51d)


What the hell is that truss? I'll give it to the Italians on one mark...they love their artistic design.

Title: Re: Cantilevers from hell
Post by: architect77 on February 06, 2010, 12:43:26 AM
Quote from: Chris on February 05, 2010, 04:19:57 PM
Italy sometimes installs these monsters:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi50.tinypic.com%2F2irralf.jpg&hash=9199505358b4725ab03b250acd9209fdd5d6bd1a)
Now I've seen everything: cable-stayed overhead signage. That's hilarious.
Title: Re: Cantilevers from hell
Post by: Michael on February 09, 2010, 09:00:03 AM
^^ I think it's pretty cool.  It reminds me of those high-rise construction cranes.
Title: Re: Cantilevers from hell
Post by: shoptb1 on February 09, 2010, 09:01:50 AM
Quote from: Michael on February 09, 2010, 09:00:03 AM
^^ I think it's pretty cool.  It reminds me of those high-rise construction cranes.

I think it looks awesome.  It's gotta be the textbook definition of 'overkill' though :)
Title: Re: Cantilevers from hell
Post by: architect77 on February 10, 2010, 12:37:23 PM
I don't like it, because this structural technology and visual expression doesn't match the task  being performed. Cable-stayed bridges are gorgeous solutions for spanning great distances. These gantries are the equivalent of little Golden Gate Bridges holding up overhead signs.

The Bay Bridge's SAS span is going to be something... For me, the most amazing aspect of this project is that some sections will rest on bedrock, while the others are anchored in mud and silt, but they're connected as one structure able to withstand an 8.0 magnitude quake. They even buried an array of pipes in the mud to hopefully channel away the water that causes liquefaction and its associated instability.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi174.photobucket.com%2Falbums%2Fw102%2Farchitect77%2Fbaybridge.jpg&hash=fcd4cee15a603bb2ff21491b851fa263c511b2b6)
Title: Re: Cantilevers from hell
Post by: thenetwork on February 11, 2010, 08:15:31 PM
Quote from: shoptb1 on February 05, 2010, 05:23:39 PM
Quote from: Chris on February 05, 2010, 04:19:57 PM
Italy sometimes installs these monsters

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.matildi.com%2Fimages%2Flotto5_gra_finale.jpg&hash=0c90ac2c69bb7ee9385daa1765a32a71b959a51d)
What the hell is that truss? I'll give it to the Italians on one mark...they love their artistic design.

The one in the foreground is wild, but I'd like to see the one in the background up close as well!
Title: Re: Cantilevers from hell
Post by: Scott5114 on February 11, 2010, 10:45:41 PM
It appears to be the same as the foreground one, but in a cantilever (half-gantry) form.
Title: Re: Cantilevers from hell
Post by: D-Dey65 on February 23, 2010, 08:47:31 AM
On the westbound Long Island Expressway service road at former Exit 54(Wicks Road), they have a whole bunch of them cluttered right next to each other, that could easily be reduced and removed.

Sorry, no pics.

Title: Re: Cantilevers from hell
Post by: joseph1723 on April 18, 2010, 05:47:51 PM
A little late but here's a new one from Ontario:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fimg44.imageshack.us%2Fimg44%2F1577%2Frscn7981.jpg&hash=c16bb23b76eb5c9fbbe5a06d610b02b77fb3ec40)

It looks like MTO is using more far reaching overheads than before, if this sign was put up a few years back it would have been on a sign bridge. Also they seemed to have learned something from Caltrans   :clap:
Title: Re: Cantilevers from hell
Post by: The Premier on April 18, 2010, 07:52:38 PM
Here's one on I-76 just past the SR 59 on-ramp in Akron:

http://maps.google.com/?ie=UTF8&ll=41.061848,-81.547158&spn=0,0.006899&z=17&layer=c&cbll=41.061864,-81.547048&panoid=pyVp7GtbJ6_LPL9NMST4xQ&cbp=12,264.29,,0,7.24 (http://maps.google.com/?ie=UTF8&ll=41.061848,-81.547158&spn=0,0.006899&z=17&layer=c&cbll=41.061864,-81.547048&panoid=pyVp7GtbJ6_LPL9NMST4xQ&cbp=12,264.29,,0,7.24)
Title: Re: Cantilevers from hell
Post by: Ian on April 18, 2010, 10:06:04 PM
I actually noticed that North and South Carolina love those extended cantilevers:

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Flh4.ggpht.com%2F_ZkmN2RrOJxw%2FS8t5VIX8XZI%2FAAAAAAAAZtQ%2FqzBSxX1-gok%2Fs640%2FIMG_5034.JPG&hash=5e9f42d874a2ce1f703d576f1401c04fbbe74ffd)

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Flh3.ggpht.com%2F_ZkmN2RrOJxw%2FS8tfkF5HUuI%2FAAAAAAAAZCY%2FtLmPcbFp1z8%2Fs640%2FIMG_5158.JPG&hash=ce63463d3746bbb43f222a63fa41a7d9e4d60caf)
Title: Re: Cantilevers from hell
Post by: thenetwork on April 19, 2010, 11:57:42 AM
Quote from: The Premier on April 18, 2010, 07:52:38 PM
Here's one on I-76 just past the SR 59 on-ramp in Akron:

http://maps.google.com/?ie=UTF8&ll=41.061848,-81.547158&spn=0,0.006899&z=17&layer=c&cbll=41.061864,-81.547048&panoid=pyVp7GtbJ6_LPL9NMST4xQ&cbp=12,264.29,,0,7.24 (http://maps.google.com/?ie=UTF8&ll=41.061848,-81.547158&spn=0,0.006899&z=17&layer=c&cbll=41.061864,-81.547048&panoid=pyVp7GtbJ6_LPL9NMST4xQ&cbp=12,264.29,,0,7.24)

Talk about a waste of metal (and tax money).  There are at least 2 sign bridges past this one letting people know of the upcoming I-76/I-77 split and which lanes are for which routes.

Title: Re: Cantilevers from hell
Post by: architect77 on April 19, 2010, 04:28:34 PM
Quote from: mightyace on February 02, 2010, 07:31:06 PM
Of the ones I've gotten so far, I think this one takes the cake:

TN SSR 255 WB @ I-65

I think that Tennessee takes the cake for the most part.....

[Edited to remove quoted images from post. No need to have the same images twice in one topic...if you're quoting a post with images, please take them out. -S.]
Title: Re: Cantilevers from hell
Post by: Marc on April 20, 2010, 11:28:46 PM
I-240 East approaching Lamar Ave. (U.S. 78) in Memphis.

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=memphis&sll=37.0625,-95.677068&sspn=51.04407,56.513672&ie=UTF8&hq=&hnear=Memphis,+Shelby,+Tennessee&ll=35.076212,-89.978027&spn=0.012995,0.013797&z=16&layer=c&cbll=35.076201,-89.97822&panoid=LsMsMs-aNjFf9A2WK6GvCg&cbp=12,83.15,,0,5.28 (http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=memphis&sll=37.0625,-95.677068&sspn=51.04407,56.513672&ie=UTF8&hq=&hnear=Memphis,+Shelby,+Tennessee&ll=35.076212,-89.978027&spn=0.012995,0.013797&z=16&layer=c&cbll=35.076201,-89.97822&panoid=LsMsMs-aNjFf9A2WK6GvCg&cbp=12,83.15,,0,5.28)
Title: Re: Cantilevers from hell
Post by: architect77 on September 02, 2010, 11:30:35 AM
Over time, metal fatigue, vibrations, and poor workmanship have resulted in about a dozen of these cantilievered structures to fall over in the past decade (across the country, only 1 in Georgia).

Rather than beefing up the members of the structural posts, Georgia issued a directive that only a "balanced butterfly" post be used to elevate advanced guide signs.

On arguably the nation's widest highways, with 6 travel lanes in each direction depending on the sign's info to navigate though the lanes, do you Georgia's elevated "Overheads" are appropriate? I don't...
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi174.photobucket.com%2Falbums%2Fw102%2Farchitect77%2Fgaped2.jpg&hash=4632d362418cb89227a417e945efefbe39137a18)
North Carolina is using sturdier structural posts:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi174.photobucket.com%2Falbums%2Fw102%2Farchitect77%2F540.jpg&hash=fa172c7adf7b56f107a26b359ed9ca03b6707ed4)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi174.photobucket.com%2Falbums%2Fw102%2Farchitect77%2Fi85ncexit132_02.jpg&hash=060b5001d9f1acb28879c3197e6591cce07dfd67)
Title: Re: Cantilevers from hell
Post by: Quillz on September 02, 2010, 03:08:18 PM
Quote from: joseph1723 on February 02, 2010, 08:05:56 PM
Here's the widest one I've seen in Ontario so far:
ON 427 NB at ON 27 collector transfer
[ snip ]

This one just has a wide BGS on it:
ON QEW Hamilton Bound at Cawthra
[ snip ]

I think MTO only started using a lot of cantilevers structures in the past five or so years. I recall almost all of the signs before then were one sign bridges.  Both of the cantilevers pictured replaced a older sign bridge though. I've seen more and more supports for cantilevers getting installed now.    
What is the significance of the blue guide sign in the background rather than the green sign? Are blue signs reserved for a different class of highway?
Title: Re: Cantilevers from hell
Post by: deathtopumpkins on September 02, 2010, 03:09:58 PM
Ontario uses blue signs on the local lanes and green signs on the express lanes in local/express setups.
Title: Re: Cantilevers from hell
Post by: thenetwork on September 02, 2010, 07:58:09 PM
Quote from: architect77 on September 02, 2010, 11:30:35 AM
Over time, metal fatigue, vibrations, and poor workmanship have resulted in about a dozen of these cantilievered structures to fall over in the past decade (across the country, only 1 in Georgia).

I remember how Michigan seemed to have an epidemic of bad overhead sign structures in the latter half of the 80s -- especially in Southeast MI.   
Title: Re: Cantilevers from hell
Post by: Ian on September 03, 2010, 11:37:23 PM
The new Rhode Island cantilevers look like they could hold up quite a load!
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Flh6.ggpht.com%2F_ZkmN2RrOJxw%2FTDp3ax1EJgI%2FAAAAAAAAfKg%2FAtziu3T-S60%2Fs640%2FIMG_7699.JPG&hash=4362a2c4414da6fb2033b7dc28a40c7ba2b08ff2)

Older New Hampshire's cantilevers are pretty bulky:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Flh6.ggpht.com%2F_ZkmN2RrOJxw%2FTEDihc88RuI%2FAAAAAAAAfvk%2FDx5a2UpUM_k%2Fs640%2FIMG_7903.JPG&hash=7e52504a75eefaa0b2db718ee19fe1bec86a6bd3)

Older Florida's cantilvers look similar to the one above:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Flh5.ggpht.com%2F_ZkmN2RrOJxw%2FS9iaDsvy0zI%2FAAAAAAAAa1Y%2FJHzpcCqJzh4%2Fs640%2FIMG_3269.JPG&hash=a19e3893fcf42f37e34f720433070023dc5e8d55)